feat: Implement IPFS functionality using Helia

- Add Helia and related dependencies for IPFS integration.
- Create IPFS service module for core IPFS operations.
- Create IPFS context provider for application-wide access.
- Modify MarkdownContent component to fetch from IPFS.
- Create IPFS uploader component for content upload.
- Create IPFS gateway fallback for offline access.
- Modify NavDataProvider to load from IPFS.
- Implement offline support and local caching.
- Create Network Status Service to monitor network status.
- Create Offline Status Component to display offline status.
- Implement Service Worker for caching app assets.
- Create Offline page.

sweb/package.json

@@ -26,12 +26,21 @@
     "vite": "^6.3.5"
   },
   "dependencies": {
+    "@helia/interface": "^5.2.1",
+    "@helia/unixfs": "^5.0.0",
+    "@libp2p/webrtc": "^5.2.12",
+    "@libp2p/websockets": "^9.2.10",
+    "@libp2p/webtransport": "^5.0.40",
     "@tailwindcss/postcss": "^4.1.6",
     "@tailwindcss/vite": "^4.1.6",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "helia": "^5.3.0",
+    "idb": "^8.0.3",
+    "libp2p": "^2.8.5",
     "lucide-svelte": "^0.509.0",
     "marked": "^15.0.11",
+    "multiformats": "^13.3.3",
     "shadcn-svelte": "^0.14.2",
     "tailwind-merge": "^3.2.0"
   }